Cartridge Longevity?

In mid '98 I purchased a Sumiko Blue Point cartridge to use with a Premiere FT-3 tonearm / VPI HW-19 Mk. III. I loved the sound right out of the box (lots of detail, crisp treble, tracked inner grooves with so little distortion they sounded like outer grooves). After about forty to fifty hours of play over a year and a half, the treble mellowed (I liked it bright, though), and inner grooves no longer sounded good. Even on mint records, the inner grooves sounded somewhat worn. It was so bad that once I got just beyond the halfway mark on any record side, I couldn't wait for it to finish so I could switch to something else (no damage to the records, though).

I called Sumiko and spoke to the technician, Jim Alexander (who generously gave of his time). He suggested using a demagnetizer. I tried the Benz, and heard no difference. Mr. Alexander had me send the cartridge back so it could be examined. He said he could find nothing wrong with it, but graciously sent me a replacement in Jan. 2000. He ruled out any tonearm problems, but suggested lowering VTA so that the tonearm was parallel to the record. He also suggested I not use the Discwasher stylus brush because it is too abrasive.

As with the old cartridge, I tracked the new one at the recommended 1.7 grams, proper alignment using a protractor, proper azimuth, always used the cueing device, lowered VTA, switched to "LP-9" stylus fluid with its soft brush, and still the same problem: inner grooves sound mistracked and worn. The records I play are scrupulously clean. I hand wash (initially) using isopropyl rubbing alcohol, and sometimes Mr. Clean for heavily soiled records. Before each play, I use a Discwasher record brush to remove light surface dust, and a Zerostat anti-static gun. The results are excellent, they sound clean (I tried the VPI record cleaner a few years back and was unimpressed with it).

Jim Alexander suggested that I didn't allow enough break in time and use time was too low (about fifty hours under two years). He suggested breaking it in for another fifty hours, but within one week's time. I did this and the cartridge did not improve, but it did not get worse either. He finally suggested I have the tonearm checked (locally as I don't have the original packing material to safely send it through the mail. I never had it as it was purchased used).

I've been very careful but a cartridge should last more than fifty hours. Mr. Alexander claims you should get at leat 1000 hours of quality play from a Blue Point, and possibly up to 3000 hours. What am I doing wrong? Not enough break in time? Not enough usage during the life of the cartridge? Or do you need to spend four figures to get longevity? This is very frustrating and any info would be greatly appreciated. Thank you.